Assembling hexagonal‐bipyramidal {Mn8Zn2} and {Mn8Zn4} clusters

Reaction between Mn(NO3)2 ⋅ 6H2O, Zn(NO3)2 ⋅ 6H2O, 1,3,5-tri(2-hydroxyethyl)-1,3,5-triazacyclohexane (H3L) and pyrazole in MeOH under basic conditions leads to the formation of the decanuclear complex [MnIII6MnII2ZnII2(L)2(pyr)4O4(OH)4(NO3)2 (MeOH)2(H2O)4](NO3)2 ⋅ Η2Ο (1 ⋅ Η2Ο). The metallic core of the cationic cluster consists of a central hexagonal-bipyramidal {MnIII4MnII2ZnII2} unit connected to two peripheral trivalent Mn centers arranged in a “trans” fashion, with one MnIII center lying above and one MnIII center below the hexagonal plane. Replacing Mn(NO3)2 ⋅ 6H2O with MnBr2 ⋅ 4H2O and repeating the same reaction leads to the formation of the related, neutral decanuclear complex [MnIII6MnII2ZnII2(L)2(pyr)4O4(OH)4Br4(H2O)2] (2), displaying the same metallic core as 1. Addition of THF to the reaction mixture that produces (2) affords the neutral dodecanuclear complex [MnIII6MnII2ZnII4(L)2(pyr)6O4(OH)4Br6(H2O)4] ⋅ 8THF (3 ⋅ 8THF), whose metallic skeleton retains the central hexagonal-bipyramidal {MnIII4MnII2ZnII2} unit found in 1 and 2 but is now connected to two peripheral {MnIIIZnII} units. Magnetic susceptibility and magnetization measurements carried out in the T=2–300 K temperature range and in fields up to B=7.0 T for all three complexes reveal dominant antiferromagnetic exchange interactions

Two unique star-like [MnIVMnIII2LnIII] clusters: magnetic relaxation phenomena

Synthesis and magnetic properties of two tetrametallic star-like [MnIVMnIII2Ln] (Ln: Gd, Dy) clusters.</p

Manganese-lanthanide metallic clusters

In the present Thesis we were involved with the synthesis, structural, magnetic and spectroscopic characterization of new Mn, Mn/LnIII and LnIII clusters, using suitable bridging ligands (H3L1, H3L2, H2L3, R-SaOH, H2amp, H3tris, H3tea, H3L4, H3L5, H3L6,H4L7, H3L8, H3L9, ΗL10 και Haib), aiming to the isolation and study of compounds with magnetically interesting properties. More specifically, in the first part of the Thesis we were involved with the synthesis of complexes that could potentially serve as structural models of the active center of photosystem II (PSII). Upon investigating the reaction system Mn/Ca(Mg)/RCOO/L1,2/Haib, we managed to isolate complexes: [MnIII2MgII(O2CPh)4(HL1)2].MeCN.H2O (1.MeCN.2H2O) [ΜnIII6CaII2(OH)2(O)2(O2CPh)6(HL2)4(aib)2(MeOH)2].2MeCN (2.2MeCN) [ΜnIII6CaII2(OH)2(Ο)2(O2CPh)6(HL2)4(aib)2(MeOH)2].2MeCN (3.2MeCN). Replacing the s-block metals with lanthanide ions and investigating various synthetic parameters, we managed to isolate and fully characterize complexes: [MnIII2MnIVLnIII(L2)2(HL2)2(naph)(NCS)(H2O)(MeOH)1.8].0.5NO3.0.5ClO4.1.8MeOH.0.6H2O (Ln: Dy, 4.0.5NO3.0.5ClO4.1.8MeOH.0.6H2O, Gd,5.0.5NO3.0.5ClO4.1.8MeOH.0.6H2O, Y, 6.0.5NO3.0.5ClO4.1.8MeOH.0.6H2O) [MnIII(L3)(NO3)(H2O)] (7) [Dy2(L3)3(MeOH)].2MeOH (8·2MeOH). In the second part of the Thesis we investigated the general Mn/ LnIII / R-SaoH reaction system in the presence or absence of various co-ligands, and we were able to isolate complexes: [MnIII2LnIII6O2(OH)2(SaO)4(Hamp)4(acac)6].3.3ΕtOH (Ln: Dy, 9.3.3ΕtOH, Gd,10.3.3ΕtOH, Tb, 11.3.3ΕtOH, Ho, 12.3.3ΕtOH, Sm, 13.3.3ΕtOH) [MnIII2DyIII6O2(OH)2(SaO)4(H2Tris)4(acac)6].3.3ΕtOH (14.3.3ΕtOH) [MnIII2LnIII6O2(OH)2(BrSaO)4(Hamp)4(acac)6].2ΕtOH (Ln: Dy, 15.2ΕtOH, Gd,16.2ΕtOH, Tb, 17.2ΕtOH, Ho, 18.2ΕtOH) [MnIII4LnIII2O2(Br-SaO)4(Htea)2(OAc)2].2MeCN (Ln: Dy, 19.2MeCN, Gd,20.2MeCN, Y, 21.2MeCN) [Mn4IIILn2IIIO2(Εt-SaO)4(Htea)2(piv)2].2MeOH (Ln: Dy, 22.2MeOH, Gd,23.2MeOH, Y, 24.2MeOH) [MnIII4Ln2IIIO2(Εt-SaO)4(Htea)2(Ph2OAc)2].2ΜeOH (Ln: Dy, 25.2MeOH, Gd,26.2MeOH, Y, 27.2MeOH) [Μn(Ph2acac)3] (29) [Μn4(MeSaOH)4(MeSaO)4] (30). In addition, we investigated the use of aldehyde (instead of oxime) ligands, and this led to complexes: [MnIII2LnIII3(L4)2(HL4)4(NO3)2]NO3 (Dy, 31.NO3, Gd, 32.NO3) [MnIII2DyIII3(Η3L5)4(Η2L5)4(HL5)(NO3)2]NO3.MeOH.H2O (33.NO3.MeOH.H2O) [MnIII2LnIII3(L6)2(H2L6)2(HL6)2(NO3)2]NO3 (Dy, 34.NO3, Gd, 35.NO3) [MnIII2Dy3(HL1)3(L1)2(acac)3] (36) [Ln6(OΗ)2(H2L4)2(HL4)2(L4)2(NO3)2(H2O)2]2NO3.MeOH (Dy, 38. 2NO3.MeOH,Gd, 39·2NO3.MeOH) [Mn2Ln2(Salicylaldehyde)4(L7)2].MeOH (Dy, 40.MeOH, Gd, 41.MeOH, Y,42.MeOH) [LnIII6(OH)2(L8)4(Htea)2].2MeOH (Dy, 43·2MeOH, Gd, 44·2MeOH) [LnIII6(OH)2(L9)4(Htea)2].2MeOH (Dy, 45.2MeOH, Gd, 46.2MeOH). Where necessary, a replacement of the MnIII ion was attempted by the AlIII diamagneticion, and this led to the isolation of six new complexes: [Αl10(OAc)10(MeO)20].xMeOH (28.xMeOH) [Dy2Al2(L4)2(ΗL4)2(NO3)2(MeOH)4] (37) [Dy6Al9(ΟΗ)14(aib)6(tea)6(ΝΟ3)6]NO3.ΜeOH.MeCN (47) [Dy(aib)3] (48) [Ln3Al2(aib)6(OH)6(H2O)9]3NO3 (Dy, 49·3NO3, Gd, 50.3NO3). Finally, we studied the coordination ability of the bulky oxime HL10 ligand towards the formation of heteronuclear Mn/Ln and homonuclear 4f clusters, and the following complexes were synthesized: [Ln4(OH)4(L10)4(Ph2acac)4].Tol (Dy, 51.Tol, Ho, 52.Tol) [Dy6(Htea)6(OAc)6].8MeOH (53.8MeOH) {Ln2[Fe(Cp2-COO)]4(Htea)2} (Dy.54, Gd.55). The complexes mentioned above have aesthetically beautiful structures and their magnetic properties have been studied in detail.Στην παρούσα Διατριβή ασχοληθήκαμε με τη σύνθεση, δομικό, μαγνητικό και φασματοσκοπικό χαρακτηρισμό νέων πλειάδων Μn, Μn/LnIII και LnIII με τη χρήση κατάλληλων γεφυρωτικών υποκαταστατών (H3L1, H3L2, H2L3, R-SaOH, H2amp, H3tris,H3tea, H3L4, H3L5, H3L6, H4L7, H3L8, H3L9, ΗL10 και Haib) με σκοπό την απομόνωση και μελέτη ενώσεων με μαγνητικό ενδιαφέρον. Κατά το πρώτο μέρος της Διατριβής στοχεύσαμε στην απομόνωση συμπλόκων που θα μπορούσαν να χρησιμεύσουν ως δομικά μοντέλα του ενεργού κέντρου του φωτοσυστήματος ΙΙ (PSII). Μελετώντας το σύστημα αντιδράσεων Mn/Ca(Mg)/RCOO/L1,2/Haib αυτό καταφέραμε να απομονώσουμε τα σύμπλοκα: [MnIII2MgII(O2CPh)4(HL1)2]MeCN.H2O (1.MeCN.2H2O) [ΜnIII6CaII2(OH)2(O)2(O2CPh)6(HL2)4(aib)2(MeOH)2]2MeCN (2.2MeCN) [ΜnIII6CaII2(OH)2(Ο)2(O2CPh)6(HL2)4(aib)2(MeOH)2]2MeCN (3.2MeCN). Aντικαθιστώντας τα μέταλλα του s-block με λανθανιδικά ιόντα και διερευνώντας διάφορες συνθετικές παραμέτρους οδηγηθήκαμε στην απομόνωση των συμπλόκων: [MnIII2MnIVLnIII(L2)2(HL2)2(naph)(NCS)(H2O)(MeOH)1.8]0.5NO3.0.5ClO4.1.8MeOH.0.6H2O (Ln: Dy, 4.0.5NO3.0.5ClO4.1.8MeOH.0.6H2O, Gd,5.0.5NO3.0.5ClO4.1.8MeOH.0.6H2O, Y, 6.0.5NO3.0.5ClO4.1.8MeOH.0.6H2O) [MnIII(L3)(NO3)(H2O)] (7) [Dy2(L3)3(MeOH)]2MeOH (8·2MeOH). Στο δεύτερο μέρος της Διατριβής διερευνήσαμε το γενικό σύστημα αντιδράσεων Mn/LnΙΙΙ/R-SaoH, παρουσία ή απουσία διαφόρων συν-υποκαταστατών. Από τη διερεύνηση αυτού του συστήματος οδηγηθήκαμε στην απομόνωση των συμπλόκων: [MnIII2LnIII6O2(OH)2(SaO)4(Hamp)4(acac)6]3.3ΕtOH (Ln: Dy, 9.3.3ΕtOH, Gd,10.3.3ΕtOH, Tb, 11.3.3ΕtOH, Ho, 12.3.3ΕtOH, Sm, 13.3.3ΕtOH) [MnIII2DyIII6O2(OH)2(SaO)4(H2Tris)4(acac)6]3.3ΕtOH (14.3.3ΕtOH) [MnIII2LnIII6O2(OH)2(BrSaO)4(Hamp)4(acac)6]2ΕtOH (Ln: Dy, 15.2ΕtOH, Gd,16.2ΕtOH, Tb, 17.2ΕtOH, Ho, 18.2ΕtOH) [MnIII4LnIII2O2(Br-SaO)4(Htea)2(OAc)2]2MeCN (Ln: Dy, 19.2MeCN, Gd,20.2MeCN, Y, 21.2MeCN) [Mn4IIILn2IIIO2(Εt-SaO)4(Htea)2(piv)2]2MeOH (Ln: Dy, 22.2MeOH, Gd,23.2MeOH, Y, 24.2MeOH) [MnIII4Ln2IIIO2(Εt-SaO)4(Htea)2(Ph2OAc)2]2ΜeOH (Ln: Dy, 25.2MeOH, Gd,26.2MeOH, Y, 27.2MeOH) [Μn(Ph2acac)3] (29) [Μn4(MeSaOH)4(MeSaO)4] (30). Επιπλέον, στο δεύτερο μέρος της Διατριβής η χρήση αλδεϋδικών υποκαταστατών (αντί οξιμικών) οδήγησε στα σύμπλοκα: [MnIII2LnIII3(L4)2(HL4)4(NO3)2]NO3 (Dy, 31.NO3, Gd, 32.NO3) [MnIII2DyIII3(Η3L5)(Η2L5)4(HL5)(NO3)2]NO3.MeOH.H2O (33.NO3.MeOH.H2O) [MnIII2LnIII3(L6)2(H2L6)2(HL6)2(NO3)2]NO3 (Dy, 34.NO3, Gd, 35.NO3) [MnIII2Dy3(HL1)3(L1)2(acac)3] (36) [Ln6(OΗ)2(H2L4)2(HL4)2(L4)2(NO3)2(H2O)2]2NO3.MeOH (Dy, 38. 2NO3.MeOH,Gd, 39·2NO3.MeOH) [Mn2Ln2(Salicylaldehyde)4(L7)2]MeOH (Dy, 40.MeOH, Gd, 41.MeOH, Y,42.MeOH) [LnIII6(OH)2(L8)4(Htea)2]2MeOH (Dy, 43·2MeOH, Gd, 44·2MeOH) [LnIII6(OH)2(L9)4(Htea)2]2MeOH (Dy, 45.2MeOH, Gd, 46.2MeOH). Σε περιπτώσεις όπου κρίθηκε απαραίτητο, έγινε προσπάθεια αντικατάστασης του ιόντος MnIII με το διαμαγνητικό ιόν του ΑlIII, και οδηγηθήκαμε στην απομόνωση έξι νέων συμπλόκων: [Αl10(OAc)10(MeO)20]xMeOH (28.xMeOH) [Dy2Al2(L4)2(ΗL4)2(NO3)2(MeOH)4] (37) [Dy6Al9(ΟΗ)14(aib)6(tea)6(ΝΟ3)6]NO3.ΜeOH.MeCN (47) [Dy(aib)3] (48) [Ln3Al2(aib)6(OH)6(H2O)9]3NO3 (Dy, 49·3NO3, Gd, 50.3NO3). Τέλος, μελετήθηκε η χημεία ένταξης του ογκώδους οξιμικού υποκαταστάτη HL10 για την απομόνωση ετεροπυρηνικών πλειάδων Mn/Ln και ομοπυρηνικών 4f συμπλόκων, καισυντέθηκαν τα παρακάτω σύμπλοκα: [Ln4(OH)4(L10)4(Ph2acac)4]Tol (Dy, 51.Tol, Ho, 52.Tol) [Dy6(Htea)6(oAC)6]8MeOH (53.8MeOH) {Ln2[Fe(Cp2-COO)]4(Htea)2} (Dy.54, Gd.55). Τα σύμπλοκα που προαναφέρθηκαν παρουσιάζουν αισθητικά όμορφες δομές και μελετήθηκαν διεξοδικά οι μαγνητικές τους ιδιότητες

A ferromagnetically coupled pseudo-calixarene [Co16] wheel that self-assembles as a tubular network of capsules

Reaction of Co(OAc)2·4H2O and Hsal in a basic MeCN solution affords the hexadecanuclear wheel [Co16(sal)16(OAc)16]·16MeCN (1·16MeCN) that displays ferromagnetic nearest neighbour exchange and has pseudo-calixarene character. Symmetry equivalent wheels self-assemble to form remarkable tubular networks of capsules in the extended structure

Metallo-Ligand Based 3d/4f Coordination Polymers: Synthesis, Structure and Magnetic Properties

Employment of N,N′-bis(2-hydroxy-4-carboxyphenyl)oxalamide (H6L) in Cu2+ chemistry afforded the mononuclear complex (Et4N)4[CuL] ⋅ 13H2O (A) which comprises a square planar [CuL]4− complex with several O donor atoms in its periphery. The 1 : 1 reaction between complex A and Ln(NO3)3 ⋅ xH2O (Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er and Yb, x=6 or 9) in 1 : 4 mixture of ethanol/water in the presence of excess of KCl yielded two families of isomorphous 3d/4f coordination polymers, namely (Et4N)0.5[K0.5(H2O)Ln(H2O)4(CuL)] ⋅ 3H2O [Ln=La(1), Ce(2), Pr(3), Nd(4), Sm(5), Eu(6) and Gd(7)] and [K(H2O)Ln(H2O)4(CuL)] ⋅ ⋅6H2O [Ln=Tb(8), Dy(9), Ho(10), Er(11) and Yb(12)]. The crystal structures of 2–4 revealed the presence of 3D coordination polymers while the crystal structure of 9 the presence of a 2D coordination polymer. In both 3d/4f families, complex A retains its original structure and serves as a “metallo-ligand”. The magnetic properties of 2–4, 7–9, 11 and 12 are discussed. © 2022 Wiley-VCH Gmb